Locating the Parents of Add Health. This project will evaluate the feasibility of an innovative design feature of the Add Health Parent Study (Add Health-PS), a study that will collect data on parents of members of the on-going National Longitudinal Study of Adolescent Health (Add Health). The Add Health-PS will complement the rich biological, genetic, social and behavioral data already collected in Add Health and create a unique source of data for two generations of families. Add Health-PS will support a rich intergenerational study by including data on both living biological parents of the Add Health respondents, regardless of whether either of these parents lived with them through-out their childhood, and any living non-biological parents or guardians who played a significant parenting role in their lives. This pilot project will assess the feasibility of implementing this Ideal Samping Plan for Add Health-PS. For a randomly selected subsample of the households of the Add Health respondents, we will evaluate: (1) the feasibility of locating these parents, especially absent parents; (2) the costs and effectiveness of alternative strategies for locating these parents; (3) the ability to contact and interview the parents we are able to locate; (4) overall effectiveness and best practices using innovative models for locating, contacting and interviewing different types of parents of adult children. No previous national survey or data collection effort has targeted locating and recruiting into a study biological and non-biological parents when their children are adults. Findings from this pilot study will inform future efforts t develop intergenerational data on family members to study such issues as the consequences of divorce and single motherhood for the health and well-being of absent fathers later in life, and the genetic transmission of diseases or health conditions and gene- environment interactions that exploit the statistical advantages of two-generation, family-based designs.